Microwave-Assisted Synthesis of Phosphorus Based Flame Retardants

Abstract

Using microwave synthesis, chemists may decrease reaction times drastically to produce, in this case, three phosphorus-based flame retardant additives in under twenty minutes to an hour.1 Traditionally, these three products typically take twenty-four to forty-eight hours with traditional reflux methods.2 The popular and daily use of vehicles, computers, televisions and other household items that can easily become fire hazards, civilization requires the means of fire prevention for these synthetically composed polymer products. Materials must have the ability to resist flames and interrupt the combustion cycle of the flame. Due to environmental concerns, a non-halogenated and phosphorus-based compound is a solution that is already in use.3 The phosphorus-based compounds are going to be synthesized into solid products to enhance thermal stability and to make handling easier. It is hypothesized that flame retardants are best in the solid phase, which allows for higher molecular weight. The synthesis process of 1,3,5-tris(diphenoxyphosphoryl)benzoate, 1,3,5-tris(phenoxyphosphoryl) dibenzoate, and 1,3,5-tris(phenoxyphosphoryl) tribenzyldicarboxylic acid were done via microwave synthesis in bulk.2 Lastly, the final products were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA) to determine each compounds capability as a high-quality flame retardant additive for polymer compounds.